In the 3d Generation Partnership Project (3GPP) system, the coordinated multi-point transmission technology, as a technology used for solving inter-cell interference so as to improve the spectral efficiency of cell edges and cells, has undergone in-depth research in the LTE R10, but because of the time, the design of some technologies has been simplified. At last, the design of channel state information pilot frequency which is compatible to CoMP is continued to be studied in R10, and the study of the other technologies are pushed off to LTE R11 or later versions.
Through the interaction of channel information of mobile users among neighboring base stations, the neighboring base stations take can certain policies to avoid the interference, or multiple base stations carry out CoMP for the mobile users, which mainly for the mobile user at cell edge, so as to reduce the interference of edge users and improve the data throughput and spectral efficiency at the cell edge. FIG. 1 is an application schematic diagram of the CoMP technology in related art. As shown in FIG. 1, base stations include a serving base station and a cooperation base station. In the drawing, H11 represents a channel from the serving cell eNB1 to the present cell user UE1, and H21 represents a channel from the serving cell eNB1 to the neighboring cell user UE2. Likewise, H22 represents a channel from the cooperation cell eNB2 to the present cell user UE2, and H12 represents a channel from the cooperation cell eNB2 to the neighboring cell user UE1.
Typically, the form of partial feedback is adopted in CoMP uplink feedback, i.e. the UE does not completely feed back the channel matrix of the present cell and does not completely feed back the channel matrix of the neighboring cell, but feeds back partial channel information instead. Specifically, the UE feeds back the Precoding Matrix Indicator (abbreviated as PMI) of the channel of the present cell, and the UE also feeds back the Worst Companion Indicator (abbreviated as WCI) of the channel of the neighboring cell.
A method for realizing CoMP is provided in the related art. The neighboring cell eNB transmission provides a downlink precoding reference signal of a beamforming matrix used thereby; the mobile terminal obtains the optimal precoding matrix indicator according to the beamforming matrix used by the neighboring cell base station; the terminal acquires the Channel Quantity Identity (abbreviated as CQI) for interference coordination between area space cells, and feeds back the obtained optimal PMI and CQI to the serving cell base station; and the serving cell base station carries out scheduling by referring to the CQI value for interference coordination between area space cells of the terminal, and uses the optimal PMI to send Preferably pre-coded signals to the UE. By means of the method, the CoMP for interference coordination between area space cells of a terminal can be achieved. The codebook optimization method used in the method is cumbersome.